The assembly: the position of object and lens--Correction of lenses for colour--Spherical aberration--Distortion of image--The human eye--The use of spectacles--The blind spot 230 Chapter XIII.--THE MICROSCOPE, THE TELESCOPE, AND THE LENIN BOYS „ 186 A RECRUITING PLACARD FOR THE INTERNATIONAL MONTHLY MAGAZINE. BY MAUNSELL B. FIELD. I would draw each stop in complete order in the days gone by when I had to.